Improvement in heating-furnaces



Heating-Furnaces.

` Paiented Nov. 3,1874.

www i UNITED STATES PATENT OFFICEe WILIJARD TWITCHELL, OF SYRACUSE, NEWYORK.

.IMPROVEMENT IN HEATING-FURNACES.

Specification forming part of Letters Patent No. 156,447, dated November3, 1874 application filed June 6, 1874.

lrapidity and without injury to the air, as is the case when it comes incontact with the heated metal surface in a dry state.

The furnace and its concentric chambers I prefer to make as set forth inthe reissue of my patent dated the 24th September, 1872, a verticalsection of which is shown at Figure l in the accompanying drawing. Fig.2 is a plan ofthe water-pan. Fig. 3 is a plan ofthe cast-iron cap.

The furnace consists, as shown in the drawing, of a combustion-chamberor fire-pot, A,

surrounded by air-chambers b c d, the air entering the outer chamber ate, its course being indicated by the arrows, rising to the top in theouter chamber, and thence descending through the second and againascending in the third, which surrounds the fire-pit, where it isthoroughly heated, and is discharged from the top through the hot-airpipes. So far the invention is covered by my patent above named; but Ihave found that I did not get the best effects, namely, rapidlyabsorbing and bearing off the heat from the re-chamber A, while the airimpinged against the highly-heated metal of the re-pit in a dry state.To effect this desirable object I place in the bottom of theair-chamber, just atthe point Where the descending column of air entersthe inner chamber, and where it is some- What warmed, an annular basinor water-pan, F, which extends around the whole circle, except the space.occupied by the ash-pit door. This is clearly seen at Fig. 2, and thedescending column of air, impinging upon the Water in the pan, becomessaturated, and its capacity to take up and bear off the heat is therebygreatly increased, While the moisture protects the air from injury as itimpinges against the iron of the nre-chamber in a highly-heated state.

Having thus fully described my improvements, I claim- The combination ofthe annular Water-pan F with the descending air-flue at its opening intothe hot-air chamber, causing the air to impinge upon the Water and passthrough its vapor before striking the hot metal of the lirechamber, asand for the purposes set forth.

` W. TWITGHELL. litnesses:

J. J. GREENOUGE, PETER B. MCLENNAN.

